The applicant proposes to investigate the hypothesis that multiple GH-regulated signaling pathways interact at various levels into networks which lead to specific responses to GH. These interactions occur at the level of transcription factors and their binding, as well as by crosstalk among more proximal signaling molecular between the GH receptor and the nucleus. To examine this hypothesis the applicant plans to analyze transcriptional regulation of the c-fos gene by GH. Four Specific Aims are proposed: (1) To define interactions among GH-regulated DNA-protein complexes associated with the c-fos gene; (2) To identify interactions among GH-responsive DNA sequences by analysis of DNA-binding proteins; (3) To examine regulation by GH of DNA-binding complexes; (4) To determine how interactions in DNA-protein complexes contribute to specificity in GH versus cytokine regulation of c-fos transcription.